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Abstract:

A thermal module includes a heat radiating unit, a heat transfer unit,
and at least one cross-flow fan. The heat radiating unit has an air inlet
and an air outlet that communicate with each other. The heat transfer
unit has a heat absorbing section attached to a heat source and a heat
dissipating section extended from the heat absorbing section to connect
to the heat radiating unit. The cross-flow fan is arranged opposite to
the heat radiating unit with an air-out side of the cross-flow fan
located adjoining to the air inlet of the heat radiating unit. With the
above arrangements, the thermal module occupies a largely reduced area
while providing largely upgraded heat dissipation effect.

Claims:

1. A thermal module, comprising: a heat radiating unit having an air
inlet and an air outlet communicating with the air inlet; a heat transfer
unit having a heat absorbing section and a heat dissipating section; the
heat absorbing section being attached to a heat source, and the heat
dissipating section being faced toward and connected to the heat
radiating unit; and at least one cross-flow fan being arranged opposite
to the heat radiating unit with one side of the cross-flow fan located
adjoining to the air inlet of the heat radiating unit.

2. The thermal module as claimed in claim 1, wherein the heat absorbing
section of the heat transfer unit is attached to one side of a seat, and
the seat has another opposite side in contact with the heat source, such
that heat generated by the heat source is transferred to the heat
radiating unit via the seat and the heat transfer unit.

3. The thermal module as claimed in claim 1, wherein the heat radiating
unit is selected from the group consisting of a radiating fin assembly, a
heat sink, and any other element capable of radiating heat therefrom.

4. The thermal module as claimed in claim 1, wherein the heat transfer
unit is selected from the group consisting of a heat pipe, a heat
spreader, a vapor chamber, and any other element capable of transferring
heat.

5. The thermal module as claimed in claim 1, wherein the heat radiating
unit includes a plurality of radiating fins, and a flow guiding passage
is defined between any two adjacent ones of the radiating fins; and the
flow guiding passages communicating with the air inlet and the air
outlet.

6. The thermal module as claimed in claim 1, wherein the cross-flow fan
includes a housing, a blade assembly, and a motor; the housing having an
air-in side and an air-out side communicating with the air-in side; the
air-out side being located adjoining to the air inlet of the heat
radiating unit; the air-out side and the air-in side together defining a
receiving space therebetween for receiving the blade assembly therein;
and the motor being arranged to an end of the housing to connect to the
blade assembly for driving the latter to rotate.

7. The thermal module as claimed in claim 6, wherein the blade assembly
includes a plurality of blades and a plurality of annular rims; the
blades being provided between any two adjacent ones of the annular rims,
and being arranged transverse to and along a circumference of the annular
rims.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to a thermal module, and more
particularly to a thermal module that utilizes a cross-flow fan to reduce
the area occupied by the thermal module while upgrading the heat
dissipation ability thereof and overcoming the problem of vibration and
noise caused by long blades of the conventionally designed fan used with
a thermal module.

BACKGROUND OF THE INVENTION

[0002] Due to the rapid development in the electronic industry, the
density of transistors contained in various kinds of chips, such as
processors, executing units and the like, also increases quickly. While
the electronic elements can process data more quickly, they also consume
more power and generate more heat during the operation thereof. For the
central processing unit (CPU) to work stably, it is necessary to use a
high-efficiency heat radiating unit to radiate the high amount of heat
produced by the CPU in operation. To maintain highly efficient heat
radiating function, there is no way but to gradually increase the volume
and weight of the heat radiating unit. However, the large-sized heat
radiating unit forms a bottleneck in the design of notebook computers,
tablet computers, smart mobile phones, and smart handheld electronic
devices that all have very limited internal space.

[0003]FIG. 1 is a perspective view of a conventional thermal module 1,
which includes a centrifugal fan 10, a heat pipe 11, and a heat radiating
unit 12. The centrifugal fan 10 produces flowing air in order to carry
away the heat transferred to the heat radiating unit 12 and achieve the
purpose of lowering the temperature of the heat-generating electronic
element. The performance of the conventional thermal module 1 is
determined by the air flow and the air pressure produced by the
centrifugal fan 10 as well as the area provided by the radiating unit 12
for heat exchange. To provide increased area for heat exchange, the
radiating unit 12 is usually designed to have radiating fins with
extended length. While the length-extended radiating fins enable the
radiating unit 12 to provide improved heat radiating effect, they also
have excessively large volume and are absolutely not suitable for use
with the notebook computer that is characterized by light weight as well
as slim and compact configuration.

[0004] To meet the requirements for light weight as well as slim and
compact configuration, all the elements in the electronic devices,
including the centrifugal fan 10, have been miniaturized as much as
possible. However, the miniaturized centrifugal fan 10 can only produce
relatively reduced air flow, which results in limited heat dissipation
effect. Meanwhile, the miniaturized centrifugal fan 10 has blades that
have relatively large areas but reduced thickness and therefore tend to
deflect and swing and accordingly produce vibration and noise when the
centrifugal fan 10 operates.

[0005] Therefore, it has become an important target of related
manufacturers to work out a way for effectively upgrading the performance
of the radiating unit 12 without increasing the volume thereof.

[0006] In brief, the conventional thermal module has the following
disadvantages: (1) having a relatively large volume; (2) providing poor
heat dissipating effect; and (3) tending to produce vibration and noise
during operation.

[0007] It is therefore tried by the inventor to develop an improved
thermal module to overcome the problems in the conventional thermal
modules.

SUMMARY OF THE INVENTION

[0008] A primary object of the present invention is to provide a thermal
module that utilizes a cross-flow fan to reduce the occupied area
thereof.

[0009] Another object of the present invention is to provide a thermal
module that provides upgraded heat dissipation ability and reduces or
improves the vibration and noise caused by deflection of excessively long
fan blades.

[0010] To achieve the above and other objects, the thermal module
according to the present invention includes a heat radiating unit, a heat
transfer unit, and at least one cross-flow fan. The heat radiating unit
has an air inlet and an air outlet communicating with the air inlet. The
heat transfer unit has a heat absorbing section and a heat dissipating
section. The heat absorbing section is attached to a heat source, and the
heat dissipating section is connected to the heat radiating unit. The
cross-flow fan is arranged opposite to the heat radiating unit with an
air-out side of the cross-flow fan located adjoining to the air inlet of
the heat radiating unit.

[0011] By including the cross-flow fan in the thermal module, the thermal
module can have effectively reduced occupied area thereof to be
advantageously used in a limited space, and the large volume of air flow
produced by the cross-flow fan is able to effectively upgrade the heat
dissipation effect of the thermal module. In addition, by using the
cross-flow fan, the problem of vibration and noise caused by the
deflection and swing of excessively long blades of other types of fans as
found in the conventional thermal module can be effectively overcome.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The structure and the technical means adopted by the present
invention to achieve the above and other objects can be best understood
by referring to the following detailed description of the preferred
embodiments and the accompanying drawings, wherein

[0013]FIG. 1 is an assembled perspective view of a conventional thermal
module;

[0014]FIG. 2 is an exploded perspective view of a thermal module
according to a preferred embodiment of the present invention;

[0015]FIG. 3A is another exploded perspective view of the thermal module
according to the preferred embodiment of the present invention; and

[0017] The present invention will now be described with some preferred
embodiments thereof and with reference to the accompanying drawings.

[0018] Please refer to FIGS. 2 and 3A that are two exploded perspective
views of a thermal module 2 according to a preferred embodiment of the
present invention, and to FIG. 3B that is an assembled view of FIG. 3A.
As shown, the thermal module 2 includes a heat radiating unit 21, a heat
transfer unit 22, and at least one cross-flow fan 23. In the illustrated
preferred embodiment, the heat radiating unit 21 is shown as a radiating
fin assembly. However, it is understood the heat radiating unit 21 is not
necessarily limited to the radiating fin assembly, but can be a heat sink
or any other element capable of radiating heat.

[0019] The heat radiating unit 21 includes a plurality of radiating fins
211, and defines an air inlet 213 and an air outlet 214, which are
communicating with each other. Any two adjacent radiating fins 211
together define a flow guiding passage 212 between them. The flow guiding
passages 212 communicate with the air inlet 213 and the air outlet 214
for guiding air at the air inlet 213 to flow toward the air outlet 214.
When the air flows through the flow guiding passages 212, heat
transferred to the radiating fins 211 is carried away by the air to the
air outlet 214 and dissipates into external environment therefrom.
Therefore, good heat dissipation effect can be efficiently achieved.

[0020] The heat transfer unit 22 can be a heat pipe, a heat spreader, a
vapor chamber, or any other element capable of transferring heat. While
the heat transfer unit 22 in the illustrated preferred embodiment is
shown as a heat pipe, it is not necessarily limited thereto. The heat
transfer unit 22 includes a heat absorbing section 221 and a heat
dissipating section 222. The heat absorbing section 221 can be directly
attached to a heat source 24, as shown in FIG. 2, or be attached to one
side of a seat 20, as shown in FIGS. 3A and 3B. The seat 20 has another
opposite side in contact with the heat source 24, which can be, for
example, a central processing unit, a south bridge chip, a north bridge
chip, a graphics chip or an executing unit, for absorbing heat generated
by the heat source 24. The heat absorbing section 221 of the heat
transfer unit 22 attached to the seat 20 further absorbs and transfers
the heat from the seat 20 to the heat dissipating section 222, from where
the heat is further transferred to the radiating fins 211 that are in
contact with the heat dissipating section 222. Finally, the heat is
radiated from the radiating fins 211 into external environment and
dissipates into ambient air.

[0021] As can be seen from FIGS. 3A and 3B, the heat dissipating section
222 is outwardly extended from the heat absorbing section 221 to connect
to the radiating fins 211 of the heat radiating unit 21. The cross-flow
fan 23 is arranged opposite to the heat radiating unit 21 and has one
side located adjoining to the air inlet 213.

[0022] The cross-flow fan 23 includes a housing 231, a blade assembly 232,
and a motor 233. The housing 231 has an air-in side 2311 and an air-out
side 2312 communicating with each other. The air-out side 2312 of the
cross-flow fan 23 is faced toward and connected to the air inlet 213 of
the heat radiating unit 21. And, a receiving space 2313 is defined
between the air-out side 2312 and the air-in side 2311 for receiving the
blade assembly 232 therein.

[0023] The motor 233 is arranged to an end of the housing 231 to connect
to the blade assembly 232 for driving the latter to rotate. The blade
assembly 232 includes a plurality of blades 2321 and a plurality of
annular rims 2322. The blades 2321 are located between any two adjacent
annular rims 2322 and are arranged transverse to and along a
circumference of the annular rims 2322.

[0024] In practical implementation, the blades 2321 and a shaft (not
shown) of the blade assembly 232 can be adjusted in length and in a
connection structure therebetween according to required air volume and
available space for the thermal module 2. Further, since the cross-flow
fan 23 is characterized by high and uniform air flows as well as low
noise production, it is able to provide effectively upgraded air volume
and overcome the problem of vibration and noise caused by the deflection
and swing of excessively long blades of fan as found in the conventional
thermal module.

[0025] Please refer to FIG. 2. When the motor 233 of the cross-flow fan 23
drives the blade assembly 232 to rotate, ambient air is guided through
the air-in side 2311 into the receiving space 2313 before being blown out
via the air-out side 2312 into the air inlet 213 of the heat radiating
unit 22 located opposite to the cross-flow fan 23. The air blown into the
air inlet 213 flows through the flow guiding passages 212 toward the air
outlet 214 while carries heat away from the radiating fins 211, so as to
achieve the effect of quickly dissipating heat into external environment.

[0026] By combining the cross-flow fan 23 with the heat radiating unit 21
and the heat transfer unit 22, the thermal module 2 of the present
invention not only effectively reduces the occupied area thereof for
advantageously using in a limited space, but also produces good heat
dissipation effect without the need of increasing the number of fans or
heat radiating units because the cross-flow fan 23 is able to effectively
increase the volume of air flow to largely upgrade the heat dissipation
effect of the thermal module 2. In addition, by using the cross-flow fan
23, the problem of vibration and noise caused by the deflected and
swinging long blades of fan as found in the conventional thermal module
can be effectively overcome.

[0027] In brief, the thermal module according to the present invention is
superior to the conventional ones due to the following advantages: (1)
being miniaturized to have a slim configuration; (2) providing upgraded
heat dissipation effect; and (3) overcoming the problem of vibration and
noise caused by thinned blades of the conventional centrifugal fan.

[0028] The present invention has been described with a preferred
embodiment thereof and it is understood the preferred embodiment is
illustrated only to facilitate easy explanation of the present invention
and not intended to restrict the present invention in any way, and many
changes and modifications in the described embodiment can be carried out
without departing from the scope and the spirit of the invention that is
intended to be limited only by the appended claims.